Introduce rabbit_runtime

Author: michaelklishin

src/rabbit_misc.erl

@@ -1206,12 +1206,11 @@ rpc_call(Node, Mod, Fun, Args, Timeout) ->
             rpc:call(Node, Mod, Fun, Args, Timeout)
     end.
 
+get_gc_info(Pid) ->
+    rabbit_runtime:get_gc_info(Pid).
+
 guess_number_of_cpu_cores() ->
-    case erlang:system_info(logical_processors_available) of
-        unknown -> % Happens on Mac OS X.
-            erlang:system_info(schedulers);
-        N -> N
-    end.
+    rabbit_runtime:guess_number_of_cpu_cores().
 
 %% Discussion of choosen values is at
 %% https://github.com/rabbitmq/rabbitmq-server/issues/151
@@ -1223,18 +1222,6 @@ report_default_thread_pool_size() ->
     io:format("~b", [guess_default_thread_pool_size()]),
     erlang:halt(0).
 
-get_gc_info(Pid) ->
-    {garbage_collection, GC} = erlang:process_info(Pid, garbage_collection),
-    case proplists:get_value(max_heap_size, GC) of
-        I when is_integer(I) ->
-            GC;
-        undefined ->
-            GC;
-        Map ->
-            lists:keyreplace(max_heap_size, 1, GC,
-                             {max_heap_size, maps:get(size, Map)})
-    end.
-
 %% -------------------------------------------------------------------------
 %% Begin copypasta from gen_server2.erl
 

src/rabbit_runtime.erl

@@ -0,0 +1,53 @@
+%% The contents of this file are subject to the Mozilla Public License
+%% Version 1.1 (the "License"); you may not use this file except in
+%% compliance with the License. You may obtain a copy of the License
+%% at http://www.mozilla.org/MPL/
+%%
+%% Software distributed under the License is distributed on an "AS IS"
+%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+%% the License for the specific language governing rights and
+%% limitations under the License.
+%%
+%% The Original Code is RabbitMQ.
+%%
+%% The Initial Developer of the Original Code is GoPivotal, Inc.
+%% Copyright (c) 2007-2018 Pivotal Software, Inc.  All rights reserved.
+%%
+
+%% This module provides access to runtime metrics that are exposed
+%% via CLI tools, management UI or otherwise used by the broker.
+
+-module(rabbit_runtime).
+
+%%
+%% API
+%%
+
+-export([guess_number_of_cpu_cores/0, get_gc_info/1, msacc_stats/1]).
+
+
+-spec guess_number_of_cpu_cores() -> pos_integer().
+guess_number_of_cpu_cores() ->
+    case erlang:system_info(logical_processors_available) of
+        unknown -> % Happens on Mac OS X.
+            erlang:system_info(schedulers);
+        N -> N
+    end.
+
+-spec get_gc_info(pid()) -> nonempty_list(tuple()).
+get_gc_info(Pid) ->
+    {garbage_collection, GC} = erlang:process_info(Pid, garbage_collection),
+    case proplists:get_value(max_heap_size, GC) of
+        I when is_integer(I) ->
+            GC;
+        undefined ->
+            GC;
+        Map ->
+            lists:keyreplace(max_heap_size, 1, GC,
+                             {max_heap_size, maps:get(size, Map)})
+    end.
+
+-spec msacc_stats(integer()) -> nonempty_list(#{atom() => any()}).
+msacc_stats(TimeInMs) ->
+    msacc:start(TimeInMs),
+    msacc:stats().